As Eurasian insects spread, red pine trees to be purged from Bear Brook State Park

By BRENDAN CLOGSTONUnion Leader Correspondent

A stand of infested red pine trees at Bear Brook State Park will likely be cleared this winter. The browning of the pine needles is a telltale sign of red pine scale infestation. (COURTESY)

An adult female red pine scale. The scale is attached to a flake of bark that was removed for inspection. (COURTESY)

Red pine trees have been a visible presence in Bear Brook State Park since the 1930s, but with a devastating and resilient invasive insect sweeping through the park's population and threatening to spread across the state, nearly all of its 118 acres of red pines are slated to be purged by the end of the winter.

All five of the large red pine stands in Bear Brook, many of which occupy the most visible stretches of forest from the road, were found to be heavily infested this summer with a foreign insect known in North America as red pine scales. The tiny, almost invisible insect uses red pines, which are similar to pines in their native habitats in Eurasia, as a host, feeding on them for three to five years until the tree dies.

The pine needles brown as the tree is infected by the bug, a telltale sign of infestation. Trees weakened by the scales are also more susceptible to bark beetles, hastening the morality rate.

As flightless insects, they rely primarily on wind and birds for mobility. Resilient to pesticides and without any natural predators in New England, however, they spread at such alarming and unchecked rates that there is only one effective response to red pine invasion in North America: kill the hosts.

"This isn't how we like to manage our parks. . It's a last resort," said Chief of Forest Management for the New Hampshire Forest Protection Bureau Ken Desmarais. "[But] if we didn't cut these stands, we would just have 120 acres of standing dead trees, and at that point we wouldn't be able to sell them, and we wouldn't have the manpower to cut them, and it would be too dangerous for people to recreate under them because they'd be falling down all the time."

Fearing that seasonal bird migrations will spread the bugs farther into New Hampshire, the bureau is hoping to clear the trees before the end of winter, with bidding on the harvesting project beginning in December. If all goes well, the harvest, in tangent with the winter cold, which the bugs are not well adapted for, will slow, if not stop their spread. The Forest Protection Bureau investigated other red pine stands in the general area, but found no evidence of infection.

Red pine scales first appeared in North America in 1946, appearing in Connecticut. According to the bureau, it's "likely" that they were introduced to North America at the 1939 New York World's Fair, where a number of exotic trees were imported for display. By the 1960s, the scales were found in New York, New Jersey, and Rhode Island, virtually wiping out the red pine populations of Connecticut and Rhode Island.

This is their first documented appearance in New Hampshire. It's been theorized by the bureau that they have been able to make a foothold in the state because of relatively warm winters in recent years.

Red pine trees, which are native to the region, were introduced to the state park in the 1930s, when they were planted by civilian conservation groups. Money was also raised by the Daughters of the American Revolution to plant and manage the red pine stands.

Whether or not the species will be reintroduced to the park, however, the bureau has yet to decide. For the moment, because the trees don't naturally grow in the "pure stand" environment in which they were planted, the bureau is considering letting the forest repopulate itself naturally.

"I think we're just going to reassess that and first see if we can get natural regeneration in," said Desmarais. "Natural regeneration fits the area better anyways: get trees that want to be growing in those soils to grow there. Instead of fighting with nature try to work with nature to grow the healthiest and most resilient forest in the park."

In the meantime, the bureau is reaching out to community for feedback and questions.

"We welcome people's comments," said Desmarais. "We really want to reach out to the public and let them know what we're doing and why, because it will be and look dramatically different after the cutting is done. [We want] them to know that there's really no other choice. It would really be irresponsible for us to walk away and let this happen because these insects would move through the state very quickly."

If a significant number of concerns and complaints are voiced, the bureau has expressed willingness to hold public meetings to explain and discuss the plan. Questions can be directed to Regional Forester Will Guinn at 271-2214, or Forest Health Program Coordinator Kyle Lombard at 464-3016. Reports of red pine scale infestation may also be directed to Lombard.